The present invention is generally related to an improvement in fluid systems and particularly to an apparatus which may be used to minimize damage to the components of fluid systems due to the effect of fluid pressure surges.
The design of many fluid systems is complicated by the necessity to provide protection from damage due to fluid pressure surges. Fluid pressure surges occur whenever a fluid which is flowing through a system experiences a sudden change in flow rate, pressure, or direction. Such sudden changes can blow out seals, jam closely fitted parts, impair operating efficiencies, create undesirable noises, and damage system components such as pressure gauges, flow meters, and the like.
Various techniques have been used to reduce or eliminate fluid surges within a fluid system. One such technique is to utilize elastomeric elements in contact with the fluid of a fluid system. The fluid pressure surges within such a fluid system deform the elastomeric elements to effect damping of the fluid pressure surges. The disadvantage of this technique is that many elastomeric materials may be adversely affected by the associated fluid, resulting in premature failure of the damping device. Placing the elastomeric element in a surrounding membrane has been suggested, but this raises the potential problem of the membrane having an undisclosed manufacturing flaw. Detection of such a flaw is extremely difficult, and when there is no means for diagnosing such a flaw, the flaw may not be discovered. Upon installation of such a flawed elastomeric element in a fluid system, the elastomeric material will be exposed to the deleterious effects of the fluid possibly resulting in a breakdown of the elastomeric material. Such a breakdown of the elastomeric material may cause contamination of the fluid and possible destruction of the fluid system components.
Another disadvantage is that the elastomeric elements may be stressed beyond the range of elasticity for such a material upon exposure to extreme fluid pressure surges. Such deformation can rapidly decrease the elastic properties of the elastomeric members reducing their ability to dampen fluid pressure surges.
In view of the foregoing, it is an object of the present invention to provide a fluid pressure surge damper having an elastomeric member encased within a flexible membrane which provides a readily discernible self-diagnostic indication of the continuity of the flexible membrane.
Another object of the present invention is to provide a fluid pressure surge damper having an elastomeric member with a maximum deformation limit.
A further object of the present invention is to provide a fluid pressure surge damper for fluid systems which is of simple construction, easy to install, requires a minimum of maintenance, is inexpensive to manufacture, has a minimum number of parts, and is efficient in operation.
In particular the presently described invention includes a fluid pressure surge damper for damping pressure surges of fluid in a fluid system. The damper comprises a housing which contains an elastomeric element which has a flexible membrane means. The flexible membrane means provides an impervious barrier between the elastomeric element and the fluid. The housing has a connector means for connecting the housing to the fluid system. The elastomeric element is retained within the housing in a predetermined position by a means which prevents the elastomeric element from impeding the flow of the fluid. The elastomeric element has an outer peripheral portion which is compressed by the flexible membrane means in response to forces imposed thereon by a pressure differential across the membrane. The pressure differential is preferably due to a subatmospheric pressure contained within the membrane.
The presently described invention includes an embodiment wherein the flexible membrane means contains a partial volume of liquid and a liquid permeable elastomeric element. Upon ultimate compression, the partial volume of liquid defines a minimum volume to which the elastomeric element will be deformed. Providing such a limit prevents damaging deformation of the elastomeric element.
Additional objects and advantages of the present invention will become apparent from a reading of the detailed description of the preferred embodiment which makes reference to the following set of drawings.